These replace one of the four Socket Button Head Cap Screws found on the Magpul Precision Rifle Stock (PRS) with a sling stud. The threaded straps that come standard with the PRS can be reversed giving a total of 8 choices for stud placement. Each BT14 comes with two Sling Studs having 10-24 threads and black polymer spacers. Weight .5 ounce.